package edu.spec.wfl.week09.class1.classroom.newclass;

public class TestString {
    public static void main(String[] args) {
        String s="abcd";//基本数据类型
        StringBuffer sbuf=new StringBuffer( "abcd");
        StringBuilder sbui=new StringBuilder("abcd");
        s="abcd";
        sbuf.insert(2,0);
        System.out.println(s);
        System.out.println(sbuf);
        System.out.println(sbui);
    }
}
